I've purchased longer ones at RadioShack before also. BestBuy and CircuitCity may also carry longer ones.
Before you order, also check
http://www.monoprice.com. They have been by far the lowest price on other cables I've purchased. Quick shipping too.
Losi 8T 1.0, Savage Flux - XL style, LST XXL, Muggy, 3.3 E-Revo Conversion and sitting outside 425hp, 831 Tq Dodge Ram Turbo Diesel. It SMOKES